Lockout for outgoing calls for telephone systems



C. V. RAICHEY -July 7, 1931.

LOCKOUT FOR OUTGOING CALLS FOR TELEPHONE SYSTEMS Filed May 22, 1930 www m mm omJ w Jl @NJ ll t 1 s L Q J Q E L.. l m.

. w NN M4 I uw QG ,\NN H .mmwmk Patented JulyY 7, 1931 f femme {CHARLES vfmcmnlor JAMAICA, NEWJQBK "ffr'es end 'first' @flyer-ting' ltolligure 1. in which a -th entire system isfdisclosed;fthefnumer'al 1' 45 represents the telephone ilstrument; having i930. smalmo. ,454;763.

rWire 735 winger 3f and ,condenser 7l to theylllle .wiref 6: ini yWhich/s:y interposed theoonclenser l8. :fllhisvwith thezexeeptionf of .the condenseig, fzis'fusuelfconstnuction.

:Ilwisn` :alsommderstood to be :old '1t-hat .when 55 fthe-ereceiver 4:issl`ifted from'the-l-ine a ,swth sinzrtheicireuitnof `(the transmitter; 2 yis-,closed mndthat@ when e the; :operator @switches- -on :the talkingucircuit-.- which; is, directe. cur1 e nt.i it .oafn'rnoty pass nthe oondensen 71 and 1 he-reOle, m60 trtzvels from the, Line wire 5,throi1gh-thetrens amtteri ci-rouitmnd back ftotha limewire 6.

x YgIn View ofy :the interpositionf the condens- `fel? 8i in; athe line` Wire ,6, the talk-ing current 'vtakes as cireuitous-.plafth froml the. transmitter m65 ltlnfmlglrfonfiotions!fpeeuliar ,-fto; thei instrunment: fof uthe: .presentL fin-YeI-ltom returning, kto the line" Wire 6 onthmopposite. side foiesaid :xconlexfiser.y

,' The wresgyl@ and la representyhrenohesfism from the line Wire 6 at opposite sidesfozf` the :rfeondmer Sia-nd. .Whenffsad -brenehes .1.0% and 11arolosedaszbyxchefswthf .the telephone -rsoreuit is 'completejustias fftherewas 11916011- =densen Suandffasethoygh thefdeyiceof themv present invenbonwwereh notqpresent. fr, A,Nor-

f muy:thewswitoh1f12z-maythe. lgeptfeloseql by .,zbhe'npertiom of wsuitablef key actuetecLlok7 fwdiogsltown. l fTJiev'sWitchm-,myfbe /loelel open oso' thatfthe oondenserfyand thbherrelementst e: fltheflockuo'ut must -be,-ree koned withY inroonusiderilgthe operation! of the system.

Y It: issobv'ousithat with rtheswitclrlg in aflopen positionfas ,showmwandhe ,condenser 8 -lnoross a the gafyI in theyline ,Wire 6 -Whioh I they; r'bnzmch wirese: 10.! auch l1; andf the swiftolgil2 urnornia-llyr-)serve toloseg it is1.,impossib1e for one lifting the receiver 4 fromutheliook 900 'fr -ftlanslniby any ,direct- .Current through theline. -f.Gm1sequea1tly-, :withuthe: switch 12,.lookedl in nthefopemposition as shown, -t is impossible to .etrummitranoutgoing mall.;y @The operation of the look out therefore, concerns theseleetive @adaptation erf-fits; parts tothe transmission of ,':thend-eeteum'ent bea/ring theinc omin ,gfrlzalls;A zvfdesription off- Which willl be the; substptnoe i; ofafthe :remaining: part of, the spegeton.

Im ,carrying out the .principles of .the invention two electro-magnets 13 anL lbare ternatively by said magnets.

, activated by the alternating current. The

sole tunctionot this magnet is to draw the armature 15 ir'ito' the position'shown vin Fig- 'ure 1. The sequence of electrical circuits resulting iny the energization of this magnet may be traced as follows:l Operator closes the ringing' circuit, alternating current passes as has heretofore been explained through the line wire 5 across the condenser?- through the line wire 6 and condenser 8 back'to the source. Subscriber upon removing there ceiver 4 from the hook closes the transmitter circuit, by-passing the condenser 7 so that the alternating current uponreachingthe point 13 yat the condenser 8 divides, partV go- 5^ ing through the condenser and thence to the source, part going through the'branch- Wires Y 19, 20 and 21 through thewindings of the elec- .ing Y) is in circuit with a pair of contacts The booster winding c is'in'circuit with Va pair of contacts c.

' "magnet 14. f

shown.

The armature' was originally in.v contactv tro-magnet 13 4and by way of the branch'wires 22 and 23 back to the line wire 6. The electro-magnet 13 being thus energizedattracts the armature 15 drawing it to the position with the pole ofthe electro-magnet 14. The

latter is provided with three windings whichl in order to avoid confusionhave'been designated by the reference characters 1f/,b and c. findings a and l) are wound in reverse directions as indicated bythe arrows.'y ..Therefore, `when windings a and b are energized at the same time, they have a choke effect ,upon *one Vanotherand vat the rsame time neutralize. the magnet .14. Winding c `is vwoundfin the same direction as `winding b `and maylbe considered a booster winding. blinding ais inY circuit with a pair of contacts a', and wind- Referring'to the pairs of contacts a and 1) these are normally open when the armature 15is in its leitward position, that'is tofs'ay, when it is against the pole vof the electro-v Whe-n the subscriber has Vlifted therec'eiver. 4and diverted a part of the alternating current of .the ringing lcircuit through the electro-magnet 13, thea-rmature-1-5 has been attracted toits right-hand position 'shown in Figure 1.

The end of bottom :Contact spring @"haS cammed upon it an inclined portionl24 of'T I one of the pairofcontacts a closir'igathepair of contacts a', and thus it closes* the i circuit through the winding a. At the saai-1e time, the end of the contact which the armaL turerhasdirectly engaged and which over?` laps one contact of the pair of contacts b,- raises that contactand closes the pair of contacts Thus' the .armature in its trav erse from left to right position simultaneous- 'T5S ly closes the pairs of 'contacts a and b and puts the windgs a and ofthe electro-magnet 14 in conditionV tobe energized. When the -v`operator switches from the alternating current ofthe ringing circuit to .the ect current-of the talking circuit, .the direct cur- VVrent cannotpass. the condenser 8 norjcan it passithe condenser` 25 kassociated v vit'hv the electro-magnet 13. Consequently, the els' tro-magnetY 13. is Vdeenergized. At this ti1n1e,g 853 however, the directl current passes simultanevously through the following circuits; from wire -19 through winding a of the electromagnet 14, through branch w1re126, through the pair of contacts a', branch wire 27, branch. 90

wire 28, andbranch wire 23, to the line wire 6.

It also 'at the Sametime traverses a circuitfrom` the'line wire 5 through the branch line 29, branch line 30 through the winding' 95 7), branch wire 31, pair of contacts` b', branch` wire 32 to theline wire 6. A balancing resistance33 'may be placed in this circuit if desired in'order'to ensure equal distribution of the direct current through both of ther windings. It is thus obvious that while the incoming call is in progress the electro-magnet 14 is deenergized and the two windings a and bhavea choke ell'ect uponone another sothat none ofthe current of the talking .105 circuit is usedin the operationjof the device. It will be understood that while current is thus -lowingthroughthe windings a and b, the electrical impulses from the distant trans niitter are permitted to. travel uninipeded to; the receiver. j 1 y When the incoming call has been received, and the receiver has Ybeen replaced upon the ibook-the transmitter circuit is broken in the usual manner and consequently, the limb -rofthe direct'current vcircuit which energizes the winding a of the electro-magnet 14 is broken, consequently the winding a is deenergized. However since the winding b receives its energy from a'point in the line wire 120 5 in advance of the transmitter circuit,the circuit through this winding is not inter-rupted. The magnet 14 therefore, becomes ener gized and' exerts anV attractive eliect upon the armature 15.VY

. 4 125 At this point it may ,be.noted.thatthe armatureV 15 is of duplex cons'tructim.l As

shown in Figure it consists of two halves 34 and 35, the half 35 havinga lateral arm 36, whichextends behind the half 34. Thus 13G when the two halves of the armature were: "said siuiit'ciitcuitincldig parallel-branches attracted by the magnet 13 in the initialf'fiev'er'sely:wound uponsaid magnet and' bestage of operation of the device, both partsi-"inig"simultaneously energized whenidirect Vmust move together, but when the armature-"current gisp'a`s's`ing through" the transmitter is attracted in the opposite direction by the'f'circuit bf the'telephone instrument, neutralelectro-magnet 14 it is possible for the half*izinggtheiinagnetism ofl said 'ret-urn magnet 54 to move away from the half 35. It is notedfdiiring vthey period lof incoming speech, vsaid in Figure 3 that the half 35 is longer thai'imbr'ancl'i' circuits emanating' from saidlin'e cirbhe and theIBfOIQ, beaIS the btllllliiicitin @fia Condgngr Whfeby, of frictional engagement with the lower coni/when said transmitter circuit is" opt-inedv by tact of the pair of contacts a. Consequently, `:th'eiplacing ofA the4r `teiephone receiver 'upon When the eleCtIO'-m2tgnt 14 iS @Belgi/Zed by the hoolgone oi'f said branch circuits is'bloclied the breaking of the circuit of the winding a," by' 'saidf condenser permitting lenerg'ization the short half 34 being unburdened, will be first attracted to the magnet 14. The pair V of contacts o which closes the circuit of the booster winding c has a cam end 37 with which the end of the short halt` 34 collides as it returns to the magnet 14, closing the paii of contacts c so that the booster winding c now becomes energized by current passing through the branch wire 38, winding c, pair of contacts c', pair of contacts branch wire 39 back to the line wire 6.

The opening of the contacts places a gap in the circuit of the windings and c so that the magnet 14 is entirely deenergized.

While I have in the above description endeavored to describe what I believe to be a preferred and practical forni of my invention, it is to be observed that the details of construction and the precise connections as shown are immaterial to the embodiment of Ythe hook switch'in the telephone instrument,

and an armature actuated by the ringing circuit for closing a shunt circuit around iirst if mentioned gap, a magnet for returning said armature, said shunt circuit including branches reversely Wound upon said magnet so as to be energized in bucking relation during the period of incoming speech, preventing return of said armature, said hook switch being in one of said branches whereby when the transmitter circuit is opened by the placing of the telephone receiver upon the hook, one of said branch circuits is` opened permit- 5 ting the other to energize said magnet for returning said armature.

2. Lock out for telephone systems comprising means for producing a gap in the line circuit in series with the gap produced at the hook switch in the telephone instrument, and

an armature actuated by the ringing circuit for closing a shunt circuit about said rst mentioned gap, said shunt circuit including said hook switch, an electro-magnet for returning said armature to normal position,

'ot'said' magnet by the other branch circuit 'for returning said armature to normal position and opening said line circuit.

3. Lock out for telephone systems as -claimed in claim 2, in which the branch circuit on the source side of said condenser is in series with a resistance, said electro-magnet being provided with a booster winding bypassing said resistance, said armature being in two parts responding successively to the stages of magnetism in said electro-magnet produced successively, by said branch circuit' and by said branch circuit enforced by said booster circuit, the part of said armature irst attracted engaging a switch for closing said booster circuit.

4. Lock out for telephone systems as claimed in claim 2, the parts of said armature being weighted so as to be in a state of indifferent equilibrium.

5. Lock out for telephone systems comprising means for producing a gap in the line cir'-` cuit in series with the gap produced by the hook switch in the telephone instrument, an armature, an electro-magnet energized by the ringing circuit, a shunt circuit about said irst mentioned gap, said shunt circuit including said hook switch, an electro-magnet on the opposite side of said armature for returning the latter to normal position, said shunt circuit including parallel branches reversely wound upon said magnet and including switches simultaneously closed by said armature when attracted by said first named electro-magnet, said branch circuits being simultaneously energized when directcurrent is passing through the transmitter circuit for neutralizing the magnetism of said electroinagnet during the period oi incoming speech, said branch circuits emanating from said line circuit on opposite sides of a condenser, whereby when said transmitter circuit is broken by the return of the telephone receiver to the hook, the passage of direct current through one of said branch circuits is blocked by said condenser permitting the energization of the second mentioned electro-magnet by the other branch circuit, said last named branch circuit including a resistance, and a booster circuit including a winding on said electro-magnet by-passing said resistance and including a switch actuated by said armature, the latter being constructed in two v y l parts attractedto said second mentioned elec? tro-magnet successively by the stages of magi I net ism of said electro-magnet successively y produced by said last mentioned branch cir- VCuit and by said branch circuit re-inforced by said booster circuit, the part first attracted closing the switch which closes said booster Vcircuit and the part last attracted opening the switcheswhich it controls, deenergizing Aboth of the active windings of said electro- Y magnet. v In testimony whereof I affix my signature.

CHARLES V. RICHEY. y 

